Management control of household appliances using RFID communication

ABSTRACT

A method and system for communicating with an associated home appliance having a micro-controller includes providing a master device that emits a signal in response to data indicative of energy operational costs. One or more RFID tags receive the master device signal. The RFID tag(s) are connected to the associated home appliance micro-controller to control the operational mode of the home appliance. Preferably, four RFID tags are responsive to four distinct frequency signal emitted by the master device and are representative of different modes of operation for the associated home appliance.

The present application claims priority from U.S. Provisional PatentApplication Ser. No. 61/097,082 filed 15 Sep. 2008, now Ser. No.12/559,703, filed 15 Sep. 2009; which provisional patent application isexpressly incorporated herein by reference, in its entirety. Inaddition, cross-reference is made to commonly owned, copendingapplication Ser. No. 12/559,636, filed 15 Sep. 2009; Ser. No.12/559,539, filed 15 Sep. 2009; Ser. No. 12/559,654, filed 15 Sep. 2009;Ser. No. 12/559,581; filed 15 Sep. 2009; Ser. No. 12/559,550, filed 15Sep. 2009; Ser. No. 12/559,597; filed 15 Sep. 2009; Ser. No. 12/559,705,filed 15 Sep. 2009; Ser. No. 12/559,561, filed 15 Sep. 2009; Ser. No.12/559,577, filed 15 Sep. 2009; Ser. No. 12/559,751, filed 15 Sep. 2009;and Ser. No. 12/559,684, filed 15 Sep. 2009.

BACKGROUND

This disclosure relates to energy management, and more particularly toenergy management of household consumer appliances. The disclosure findsparticular application to changing existing appliances via add-onfeatures or modules, and incorporating new energy saving features andfunctions into new appliances. More particularly, this disclosurerelates to a method of communicating data between a master device andone or more slave devices using radio-frequency identification (RFID).

Currently utilities charge a flat rate, but with increasing cost of fuelprices and high energy usage at certain parts of the day, utilities haveto buy more energy to supply customers during peak demand. Consequently,utilities are charging higher rates during peak demand. If peak demandcan be lowered, then a potential huge cost savings can be achieved andthe peak load that the utility has to accommodate is lessened.

One proposed third party solution is to provide a system where acontroller “switches” the actual energy supply to the appliance orcontrol unit on and off. However, there is no active control beyond themere on/off switching. It is believed that others in the industry ceasesome operations in a refrigerator during on-peak time.

For example, in a refrigerator most energy is consumed to keep averagefreezer compartment temperature at a constant level. Recommendedtemperature level is based on bacteria multiplication. Normallyrecommended freezer temperature for long (1-2 month) food storage is 0degrees F. Research shows that bacteria rise is a linear function of thecompartment temperature, i.e., the lower the temperature the lower thebacteria multiplication. Refrigerator designers now use this knowledgeto prechill a freezer compartment (and in less degree a refrigeratorcompartment also) before defrost, thus keeping an average temperatureduring time interval that includes before, during, and after defrost atapproximately the same level (for example, 0 degrees F.).

There are also currently different methods used to determine whenvariable electricity-pricing schemes go into effect. There are phonelines, schedules, and wireless signals sent by the electrical company.One difficulty is that no peak shaving method for an appliance such as arefrigerator will provide a maximal benefit. Further, differentelectrical companies use different methods of communicating periods ofhigh electrical demand to their consumers. Other electrical companiessimply have rate schedules for different times of day.

Electrical utilities moving to an Advanced Metering Infrastructure (AMI)system will need to communicate to appliances, HVAC, water heaters, etc.in a home or office building. All electrical utility companies (morethan 3,000 in the US) will not be using the same communication method tosignal in the AMI system. Similarly, known systems do not communicatedirectly with the appliance using a variety of communication methods andprotocols, nor is a modular and standard method created forcommunication devices to interface and to communicate operational modesto the main controller of the appliance. Although conventionalWiFi/ZigBee/PLC communication solutions are becoming commonplace, thisdisclosure introduces numerous additional lower cost, reliable solutionsto trigger “load shedding” responses in appliances or other users ofpower. This system may also utilize the commonplace solutions as partsof the communication protocols.

BRIEF DESCRIPTION OF THE DISCLOSURE

The present disclosure reduces power consumption during on-peak hours byreducing the energy demand on the power generation facility, and alsoenabling the user/consumer to pay less to operate the appliance on anannual basis.

This disclosure is a low-cost alternative to using expensive orcomplicated methods of determining when peak electrical rates apply. Forexample, when the refrigerator is in peak shaving mode (or it could beprogrammed to do this constantly), an ambient light sensor determineswhen it is morning, and then stays in energy-saving mode for apredetermined number of hours. Preferably, the system will need acounter to know that the room has been dark for a predetermined numberof hours. When the lights come on for a certain length of time, then thesystem knows, for example, that it is morning.

This disclosure provides a peak-shaving appliance such as arefrigerator, including a method to determine when to go intopeak-shaving mode without using additional components, or componentsthat have another purpose, and provides a high percentage of the maximumbenefit for negligible cost. The two components needed for this are anambient light sensor and a timer. The kitchen will be dark for anextended period of time while everyone is sleeping. The light sensor andthe timer will be used to determine that it is nighttime and morning canbe determined by the light sensor. When the refrigerator determines itis morning, the timer will be used to initiate peak shaving mode aftersome delay time. For example, peak shaving mode could start three hoursafter it is determined morning starts. Similarly, the ambient lightsensor can also be used for dimming the refrigerator lights. Thisdisclosure advantageously uses ambient light to determine when to startpeak shaving.

An appliance interface can be provided for all appliances leaving themodule to communicate with the AMI system. The system provides forappliance sales with a Demand Side Management capable appliance. TheDemand Side Management Module (DSMM) is provided to control the energyconsumption and control functions of an appliance using a communicationmethod (including but not limited to PLC, FM, AM SSB, WiFi, ZigBee,Radio Broadcast Data System, 802.11, 802.15.4, etc.). The modularapproach will enable an appliance to match electrical utilitycommunication requirements. Each electrical utility region may havedifferent communication methods, protocol methods, etc. This modularapproach allows an appliance to be adapted to a particular geographicalarea of a consumer or a particular electrical provider. The module canbe added as a follow on feature and applied after the appliance isinstalled. Typical installations could include an integral mountedmodule (inside the appliance or unit) or an externally mounted module(at the wall electrical receptacle or anywhere outside the appliance orunit). The module in this disclosure provides for 2 way communicationsif needed, and will provide for several states of operation—forexample, 1) normal operation, 2) operation in low energy mode (but notoff), and 3) operation in lowest energy mode.

This module could be powered from the appliance or via a separate powersupply, or with rechargeable batteries. The rechargeable batteries couldbe set to charge under off-peak conditions. With the module powered fromthe appliance, the appliance could turn it off until the applianceneeded to make a decision about power usage, eliminating the standbypower draw of the module. If powered separately, the appliance could goto a low energy state or completely off, while the module continued tomonitor rates.

Use of RFID tags in one proposed system should offer significant savingssince the RFID tags have become very low cost due to the proliferationof these devices in retail and will effectively allow the enabledappliance to effectively communicate with the utility meter (e.g.,receive signals from the utility meter). This system makes it very easyfor a customer to manage energy usage during peak demand periods andlowers the inconvenience level to the customer by not shutting offappliances in the home by the utility. When local storage and localgeneration are integrated into the system, then cost savings are seen bythe customer. This system also solves the issue of rollingbrownouts/blackouts caused by excessive power demand by lowering theoverall demand. Also, the system allows the customer to pre-programchoices into the system that will ultimately lower utility demand aswell as save the customer money in the customer's utility billing. Forinstance, the customer may choose to disable the defrost cycle of arefrigerator during peak rate timeframes. This disclosure provides forthe controller to “communicate” with the internal appliance controlboard and command the appliance to execute specific actions with nocurtailment in the energy supply. This disclosure further provides amethod of communicating data between a master device and one or moreslave devices using RFID technology. This can be a number of states orsignals, either using one or more passive RFID tags that resonate atdifferent frequencies resonated by the master, or one or more activeRFID tags that can store data that can be manipulated by the masterdevice and read by the slave device(s). The states in either the passiveor active RFID tags can then be read by the microcontroller on the slavedevice(s) and appropriate functions/actions can be taken based uponthese signals.

A system for controlling an associated home appliance (e.g.,refrigerator, range, washer, dryer, water heater, dishwasher, microwave,air conditioner, etc.) includes a microcontroller operatively associatedwith each home appliance. A master device receives data relating toenergy costs, for example, and emits a signal indicative of the data. Atleast one RFID tag is operatively associated with the microcontroller ofthe associated home appliance. The RFID tag receives the signal suchthat the microcontroller controls the operational mode of the associatedhome appliance in response to the emitted signal.

The RFID tag may be an active tag having a memory selectively altered inresponse to the signal emitted from the master device.

The RFID tag may be a passive tag and preferably plural passive RFIDtags are associated with the microcontroller of an associated homeappliance to provide different signals indicative of different energysavings operational modes.

The master device emits signals at different first, second, third, andfourth frequencies (for example) and a respective one of first, second,third, and fourth RFID tags is responsive to one of the four frequencieswhereby the associated home appliance is actuated into a desired mode ofoperation.

The different modes of operation of an associated home appliance aredirected to desired energy saving operational states.

Multiple associated home appliances may be provided in a home with eachof the first RFID tags responsive to the first frequency signal from themaster device, and the second frequency signal operatively communicateswith each of the second RFID tags.

A method of communicating with an associated home appliance includesproviding a master device that emits at least a first signal in responseto data indicative of energy operational costs. The method furtherincludes providing at least a first RFID tag that receives the masterdevice signal and an associated home appliance micro-controller controlsthe operational mode of the home appliance.

The method further includes storing data within an active RFID tagmemory and selectively manipulating the data in the active RFID tag bythe master device.

The method includes the master device emitting signals at first andsecond different frequencies for communicating with at least first andsecond RFID tags, respectively.

The RFID tags are passive tags in another embodiment and resonate inresponse to a select frequency signal from the master devicerepresentative of different modes of operation for the associated homeappliance.

Another exemplary embodiment uses continuous coded tones riding oncarrier frequencies to transmit intelligence, for example, when one ismerely passing rate information such as rate 1, 2, 3, or 4, using thetones to transmit the signals. One could further enhance the details ofthe messaging by assigning a binary number to a given tone, thusallowing one to “spell out” a message using binary coding with multipletones. The appliance microcomputer would be programmed to respond to agiven number that would arrive in binary format.

One advantage of this approach is that customers have complete controlof their power. There have been proposals by utilities to shut offcustomers if they exceed demand limits or increase the number of rollingbrownouts. This method also gives a customer finer granularity in theirhome in terms of control. A customer does not have to load shed a roomjust to manage a single device.

This disclosure also advantageously provides modes of load shedding inthe appliance, lighting, or HVAC other than “on/off” to make thesituation more acceptable from the perspective of the customer.

An advantage of the present disclosure is the ability to produceappliances with a common interface and let the module deal with theDemand Side Management.

Another advantage is the ability to control functions and featureswithin the appliance and/or unit at various energy levels, i.e., asopposed to just an on/off function.

Another advantage is that the consumer can choose the module or choosenot to have the module. If the module is chosen, it can be matched tothe particular electrical utility service provider communication methodof the consumer.

Another benefit is the increased flexibility with an associatedelectrical service provider, and the provision of several modes ofoperation (not simply an on/off mode). The module can be placed orpositioned inside or outside the appliance and/or unit to provide demandside management.

Still other benefits relate to modularity, the ability to handlemultiple communication methods and protocols without adversely impactingthe cost of the appliance, opening up appliances to a variety ofprotocols, enabling demand side management or energy management, and/orproviding for a standard interface to the appliance (for example,offering prechill and/or temperature set change during on-peak hours).

Low cost, reliable RF transmissions within the home, rather than usingindustrial solutions such as PLC or Zigbee solutions which aresignificantly more costly than the aforementioned system.

This disclosure provides a lower cost alternative to Wi-Fi/ZigBee/PLCcommunications solutions, and provides significant savings due to thelow costs associated with RFID tags as a result of the proliferation ofthese devices in other commercial uses. Still other features andbenefits of the present disclosure will become apparent from reading andunderstanding the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-8, 9A, 9B, and 10-21 illustrate various systems and method ofexemplary embodiments described herein.

FIGS. 22-24 schematically show an exemplary embodiment of an RFIDcommunication system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one embodiment, a more advanced system is provided to handle energymanagement between the utility and the homeowner's appliances. The term“homeowner” is used herein to refer to the user of the appliances servedby the utility, and should be understood to include renters, orcommercial or institutional users of appliances or other utilitycustomers that operate appliances. The system can include one or more ofthe following: a controller, utility meter, communication network,intelligent appliances, local storage, local generator and/or demandserver. Less advanced systems may actually allow the appliance to“communicate directly with the utility meter or mesh network through theDSSM (Demand Side Management Module) (FIG. 1). The demand server is acomputer system that notifies the controller when the utility is in peakdemand and what is the utility's current demand limit. A utility metercan also provide the controller the occurrence of peak demand and demandlimit. The demand limit can also be set by the home owner. Additionally,the homeowner can choose to force various modes in the appliance controlbased on the rate the utility is charging at different times of the day.The controller will look at the energy consumption currently used by thehome via the utility meter and see if the home is exceeding the demandlimit read from the server. If the demand limit is exceeded, thecontroller will notify the intelligent appliances, lighting andthermostat/HVAC (FIG. 2).

Each intelligent appliance has a communication interface that linksitself to the controller (FIG. 3). This interface can be power-linecarrier, wireless, and/or wired. The controller will interact with theappliance and lighting controls as well as thermostat (for HVAC) toexecute the users preferences/settings.

Enabled appliances receive signals from the utility meter and help lowerthe peak load on the utility and lower the amount of energy that theconsumer uses during high energy cost periods of the day. There areseveral ways to accomplish this, through wireless communication (ZigBee,WiFi, etc) or through PLC (power line carrier) communication.Alternatively, using passive RFID tags that resonate at differentfrequencies resonated by the master, or one or more active RFID tagsthat can store data that can be manipulated by the master device andread by the slave devices(s) is an effective and potentially lower costcommunication solution since there is no protocol. Rather, a pulse ofenergy at a particular frequency will allow a low cost method with anopen protocol for transmitting/communicating between a master device andone or more slave devices, and appropriate functions/actions can betaken based upon these signals.

The interaction between controller and appliances can occur in two ways.For example, in one scenario during a peak demand period, the controllerwill receive a demand limit from the utility, demand server or user. Thecontroller will then allocate the home's demand based on two factors:priority of the appliance and energy need level (FIG. 4). The prioritydictates which appliances have higher priority to be in full or partialenergy mode than other appliances. Energy need dictates how much energyis required for a certain time period in order for that appliance tofunction properly. If the appliance's energy need is too low to functionproperly, the appliance moves to a normal mode or a higher energy needlevel. The energy saving mode is typically a lower energy usage mode forthe appliance such as shutdowns of compressors and motors, delayedcycles, higher operating temperatures in summer or lower operatingtemperatures in winter until the peak demand period is over. Once thedemand limit is reached, the appliances will stay in their energy modeuntil peak demand is over, or a user overrides, or appliance finishesneed cycle or priority changes. The controller constantly receivesstatus updates from the appliances in order to determine which statethey are in and in order to determine if priorities need to change toaccomplish the system goals.

In a second scenario, for example, a set point is provided. During apeak demand period, the controller will tell each appliance to go intopeak demand mode (FIG. 5). The appliance will then go into a lowerenergy mode. The customer can deactivate the energy savings mode byselecting a feature on the appliance front end controls (i.e. userinterface board) before or during the appliance use or at thecontroller. The controller can also communicate to a local storage orpower generation unit. This local unit is connected to the incomingpower supply from the utility. The controller notifies the storage unitto charge when it is not in peak demand, if a storage unit is includedand available. If the storage unit has enough energy to supply theappliances during peak demand, then the controller will switch thehome's energy consumption from the utility to the storage unit. The unitcan also be local generator/storage such as solar, hydrogen fuel cell,etc.

The central controller handles energy management between the utility andhome appliances, lighting, thermostat/HVAC, etc. with customer choicesincorporated in the decision making process. The controller may includenotification of an energy saving mode based on demand limit read fromone or more of a utility meter, utility, demand server or user. Anenergy savings mode of an appliance can thereby be controlled orregulated based on priority and energy need level sent from thecontroller and/or the customer (FIG. 6). Likewise, consideration to useof local energy storage and use of a local generator to offset peakdemand limit can be incorporated into the energy managementconsiderations, or provide the ability to override mode of energysavings through the controller or at the appliance, lighting, orthermostat/HVAC (FIGS. 7 and 8).

The present disclosure has the ability for the home to shed loads inpending brown-out or black-out situations, yet have intelligence toprevent an improper action such as shutting down the refrigerator forextended timeframes that might compromise food storage safety.

How much energy the appliance consumes in peak demand is based onpriority of the device and the energy need level. If the appliance'spriority is high, then the appliance will most likely not go into asaving mode. The energy need level is based on how little energy theappliance can consume during peak demand and still provide the functionsetting it is in (i.e. in a refrigerator, ensuring that the temperatureis cool enough to prevent spoiling). It will also be appreciated that anappliance may have multiple energy need levels.

The controller will be the main product with the communication andsettings control incorporated within future appliances. Specific meterswill be selected so that the controller can read the demand usage. It isintended that the demand server will possibly be purchased or leased tothe utility.

A method is provided for constructing an appliance designed to performany key function, the appliance comprises of several mechanical andelectrical elements controlled by a main controller. This maincontroller has a port for receiving information regarding theoperational state of the appliance. The port also has a user interfaceor switch which could be used to override the information received bythe controller through the port. Two-way or one-way communicationdevices may be connected to the port. These communication devices willreceive signals from a remote controller, process those signals and as aresult communicate an operational state to the main controller of theappliance. This operational state is communicated to the main controllerby one or more remote controllers in a specific format determined by theappliance. These signals from the remote controller(s) could be based ona variety of communication methods and associated protocols. Onreceiving the operational state signal, the appliance main controllercauses the appliance to run a predetermined operational mode. Theseoperational modes are designed into the appliance(s) and result indifferent resource consumption levels or patterns, even delaying use.Resources could include energy, water, air, heat, sunlight, time, etc.In future appliance models, the consumer might be given the authority tomodify the appliance responses to a given rate signal. The consumerwould be presented a “check box” of potential response modes and allowedto choose within set parameters. For instance, the consumer might beallowed to choose the amount of temperature adjustment a refrigeratorwill make in response to a high utility rate.

A method of communicating data between a master device and one or moreslave devices may advantageously use continuous tone-coded transmissionsystem. This can be a number of states or signals, either using one ormore continuous tones that signify different rate states coming from thehome area network (from meter) or the utility. Additionally, one couldsend a combination of tones to transmit binary messages using a fewtones. The slave devices will incorporate a receiver that receives thecarrier frequency and then decodes the continuous tone which correspondsto the particular state of the utility rate. Once the “receiver board”detects the tone, then the downstream circuitry will trigger theappropriate response in the appliance. The carrier frequency in thisscheme can be numerous spectrums, one being the FM broadcast band or aspecific FM band allocated by the FCC for low level power output. Theadvantage of broadcast band FM is the low cost of such devices and thepotential to penetrate walls, etc. within a home with very low levels ofpower due to the long wavelength of the 89-106 Mhz carrier. This processis used today in 2-way radio communications to reduce the annoyance oflistening to multiple users on shared 2-way radio frequencies. Theprocess in these radios is referred to as CTCSS (continuous tone-codedsquelch system) and would find application in this end use.

Generally, it is not known to have modular interfaces that can receivesignals from a control source. Also, no prior arrangements havefunctioned by addressing the control board of the appliance with asignal that directs the appliance to respond.

Thus, by way of example only, the structure and/or operation of arefrigerator (FIG. 9, although other appliances are also represented)may be modified or altered by reducing the temperature, especially inthe freezer compartment pre on-peak time and further temporarily providea compartment temperature increase to shave on-peak load. Specifically,defrost operation could be delayed until off-peak time. Alternatively orconjunctively, the freezer and refrigerator temperature setpoints may beset to maintain less compressor on time during on-peak demand times.Similarly, the refrigerator/freezer could be programmed so that lightswill not be permitted to come on or the lights must be dimmed lightsduring on-peak demand times. During on-peak demand times, the fanoperating speeds can be reduced, and/or compressor operating speedreduced in order to reduce energy consumption. Still another option isto reduce the delay time for the door alarm to sound during on-peaktime. Other power load reducing measures in a refrigerator may include(reducing before on-peak hours) the temperature of the freezer andrefrigerator compartments in a refrigerator (prechill) and slightlyincrease temperature setting during on-peak rates. For example, justbefore peak rate time, the temperature setting could be decreased by 1-2degrees (during off-peak rates). Some communication line with theelectrical company could be established. Thus, the electrical companymay be able to send a signal in advance to prechill the refrigerator (orin the case of an air conditioner, decrease the room temperature duringoff-peak rates as a pre-chill maneuver) and, in turn, increase thetemperature setting during on-peak rates.

Still other energy consuming practices of the exemplary refrigeratorthat may be altered include turning the ice-maker off during on-peakdemand times, or disabling the crushed ice mode during on-peak demandtimes. Alternatively, the consumer may be given the ability to selectvia a user interface which items are incorporated into the on-peakdemand via an enable/disable menu, or to provide input selection such asentry of a zip code (FIG. 10) in order to select the utility company andtime of use schedule (FIG. 11), or using a time versus day of the weekschedule input method (FIGS. 12-13).

The user interface may also incorporate suggested energy saving tips orshow energy usage, or provide an indicator during on-peak mode, orprovide a counter to illustrate the energy impact of door opening, orshowing an energy calculator to the consumer to serve as a reminder ofthe impact of certain selections/actions on energy use or energyconservation (FIGS. 14-19).

One path that is being pursued from the appliance perspective is toallow the onboard CPU (microprocessor) of the appliance to determine howto respond to an incoming signal asking for a load shedding response.For example, the CPU will turn on, turn off, throttle, delay, adjust, ormodify specific functions and features in the appliance to provide aturndown in power consumption (FIG. 20). FIG. 21 defines specificallyexemplary modes of what are possible. The main feature here is theenabling of the main board microprocessor or CPU to execute actions inthe appliance to deliver load shedding (lowering power consumption atthat instant). The actions available in each appliance are only limitedto the devices that the CPU has control over, which are nearly all ofthe electrical consuming devices in an appliance. This may work betterwhere the appliance has an electronic control versus anelectromechanical control.

Of course, the above description focuses on the refrigerator but theseconcepts are equally applicable to other home appliances such asdishwashers, water heaters, washing machines, clothes dryers,televisions (activate a recording feature rather than turning on thetelevision), etc., and the list is simply representative and notintended to be all encompassing.

Likewise, although these concepts have been described with respect toappliances, they may find application in areas other than appliances andother than electricity usage. For example, a controller that acts as anintermediary between the utilities meter and the appliance interpretsthe utility signal, processes it and then submits this signal to theappliance for the prescribed reaction. In a similar fashion, thecontroller may find application to other household utilities, forexample, natural gas and water within the home. One can equip the waterand gas meters to measure flow rates and then drive responses to a gaswater heater or gas furnace precisely like the electrical case. Thiswould assume that one might experience variable gas and water rates inthe future. Secondly, the flow meters being connected to the controllercould provide a consumer with a warning as to broken or leaking waterlines by comparing the flow rate when a given appliance or appliancesare on to the normal consumption. In cases where safety is a concern,the system could stop the flow of gas or water based on the dataanalysis.

Another feature might be the incorporation of “remote subscription” forthe utility benefit. In some cases, the utility will be providingcustomers discounts/rebates for subscribing to DSM in their appliances,hot water heaters, etc. The “remote subscription” feature would allowthe utility to send a signal that would “lockout” the consumer fromdisabling the feature since they were on the “rebate” program.

Another feature that the controller lends itself to is the inclusion of“Remote diagnostics”. This feature would allow the appliance to send asignal or message to the controller indicating that something in theappliance was not up to specifications. The controller could then relaythis signal to the utility or to the appliance manufacturer via thevarious communication avenues included into the controller (i.e., WIFI,WIMAX, Broadband, cell phone, or any other formats that the controllercould “speak”).

In the case of a remote subscription, the utilities today rely on thehonesty of their subscribers to leave the DSM system functional. Somepeople may receive the discounts/rebate and then disable the featurethat drives the load shedding. With this system, the utility can ensurethat the feature will be enabled and provide the proper load shedding.

With continued reference to FIGS. 1-21, attention is now directed toFIGS. 22-24 which show more particular details of a system and method ofcommunicating data between a master device and one or more slave devicesusing RFID technology. Specifically, meter 100 is provided at the homeand operatively associated with either utility or localstorage/generator 102, 104, respectively, or both. As describedpreviously, the utility may issue a signal to the meter indicative ofthe cost of energy. This information is transmitted to a controller,such as a home energy controller or home energy module (HEM) 110, thatcan be located adjacent the meter, or within the home. One or more homeappliances 120 each include a microcontroller 122 that operativelycontrols the individual home appliance. The communication between themaster device (controller 110) and one or more slave devices(microcontrollers 122) controls operation of each of a respective homeappliance 120. Particularly, at least one RFID tag 130, and as willbecome more apparent below, second, third, and fourth RFID tags 132,134, 136, respectively, each communicate with a respectivemicrocontroller of a home appliance. Thus, as seen in FIG. 22, a singlecontroller/HEM communicates with multiple home appliances 120. Anemitter 138 is part of the controller/HEM 110, and emits one or moredistinct frequency signals indicative of the operational energy costsassociated with data received from the utility or other device.

In the embodiment illustrated in FIGS. 22 and 23, any one home appliance120, 120′, etc. includes multiple RFID tags. Four individual RFID tags130, 132, 134, 136 are shown for each appliance. Each tag communicateswith the associated microcontroller of that appliance and resonates inresponse to a particular frequency emitted by the transmitter ortransceiver that has a variable frequency oscillator. Thus, thetransmitter 138 emits a select frequency. At the selected frequency, oneof the RFID tags is responsive, i.e., resonates. This is indicative of afirst state, level 1, 2, 3, or 4 such as “low”, “medium”, “high”,“critical”, and representing, for example, operational costs associatedwith the energy source. Since the RFID tag 130 responds to a firstfrequency, the microcontroller 122 then provides the opportunity for theassociated home appliance to operate in a predetermined manner, forexample, associated with a low operational cost mode. Likewise, if thetransmitter 138 is changed to a different, second frequency, then thesecond RFID tags 132, 132′, etc. associated with respective homeappliances 120, 120′, etc. are informed that a different operationalcost structure is active and the consumer has the opportunity to acceptor reject a programmed operation of the home appliance. Thus, in aone-way operation, each of the RFID tags 130-136 is preferably a passiveRFID tag, i.e., a tag that includes an integrated circuit and antennaresponsive to a select frequency.

There is typically enough separation between the preselected frequenciesthat only one RFID tag is resonating at any one time. Binary digits canalso be assigned to the RFID tags, and in this way can easilycommunicate with the microcontroller via the assigned binary digits. Forexample, the first RFID tag 130 may be representative of a binary “zero”[00]. Similarly, the second RFID 132 tag is a binary “one” [01], thethird RFID tag 134 is a binary “two” [10], and the fourth RFID tag 136is a binary “three” [11]. Required power for the passive RFID tag isvery low, and it is also understood that the RFID communicationtechnology has only a limited range so that communication betweenadjacent homes in the neighborhood is unlikely to occur. It will also beunderstood that even if there was some bleed-over from one home toanother, it is likely that most homes in a sub-division will bereceiving the same state of operation or costs, since the homes arelikely associated with the same utility. Moreover, each home has theoption to accept how to respond at these various levels so that oneneighbor that receives a level “three” [11] communication may have theHEM pre-programmed to “always accept” the suggested action for theappliance(s), while a second consumer may opt for “let consumer makedecision” when a level “three” [11] is encountered. Thus, it is evidentthat a particular consumer can make the decisions on how one or moreappliances may respond to a particular signal.

It is also contemplated that two-way communication between the RFID tagand the transmitter may occur. Use of an active RFID provides limitedpower in the RFID tag. That is, it is possible to change the state ofthe memory 142 associated with an active RFID tag 140 (FIG. 24). In thismanner, the transmitter can have a bit that is changed as a result ofreceiving a signal from the active tag, and thereby know what the stateof the appliance is. It is expected that the power for an active RFIDtag will come from the appliance main board. By changing a bit in thetransmitter in response to the signal emitted by the active tag, theconsumer/utility can determine the state of the appliance. Since thecontroller/home energy manager has a receiver that communicates with theutility, the output side of the home energy manager is a preferred useof this type of communication.

Each RFID tag is relatively inexpensive, on the order of five to tencents per passive RFID tag and provides an inexpensive, open protocolmanner to communicate between the controller/HEM and respective homeappliances. The RFID communication system is also advantageous in thatthe communications can penetrate walls, and is easily implemented.Although the representative example describes the controller/HEM as thetransmitter, it is also understood that the transmitter can be locatedat the meter.

In summary, the enabled appliances can receive signals from the utilitymeter and help lower the peak load on the utility, and likewise, lowerthe amount of energy that the consumer uses during high energy costperiods of the day. The RFID system is an effective wirelesscommunication where one or more signals can be transmitted from themaster device to one or more slave devices through a low-cost, openprotocol. The simple hardware and software, i.e., no protocol, aredesirable since transmission is a simple pulse of energy on a particularfrequency.

The invention has been described with reference to the preferredembodiments. Obviously, modifications and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the invention be construed as includingall such modifications and alterations.

What is claimed is:
 1. A method comprising: emitting a first signal and a second signal from a master device in response to data indicative of energy operational costs, the first signal and the second signal having, respectively, a first frequency and a second frequency, wherein the first frequency is different from the second frequency; and receiving the first signal and the second signal at a home appliance incorporating a first RFID tag and a second RFID tag responsive to, respectively, the first frequency of the first signal and the second frequency of the second signal to control operation of the home appliance.
 2. The method of claim 1, wherein one of the first RFID tag and the second RFID tags are an active RFID tag having a memory for storing data therein.
 3. The method of claim 2 further comprising selectively manipulating the data in the active RFID tag by the master device.
 4. The method of claim 1, further comprising providing a third RFID tag and a fourth RFID tag in communication with the associated home appliance controller, wherein the third RFID tag and the fourth RFID tag resonate at frequencies that are different from each other and from the first RFID tag and the second RFID tag.
 5. The method of claim 4, further comprising emitting a third signal and a fourth signal from the master device at, respectively, a third frequency and a fourth frequency for communicating with the third RFID tag and the fourth RFID tags, respectively.
 6. The method of claim 5 wherein the first RFID tag, the second RFID tag, the third RFID tag, and the fourth RFID tag are passive tags and wherein the first signal, the second signal, the third signal, and the fourth signal are representative of low, medium, high, and critical modes of operation for the associated home appliance.
 7. A system comprising: a master device adapted to receive data relating to energy cost and for emitting a first signal at a first frequency and a second signal at a second frequency indicative of same; a home appliance incorporating a first RFID tag and a second RFID tag responsive to, respectively, the first frequency of the first signal and the second frequency of the second signal to control operation of the home appliance from the master device, the appliance also comprising a microcontroller, wherein the microcontroller changes operation of the home appliance between a first state and a second state in accordance with the response to the first signal by the first RFID tag and the response to the second signal by the second RFID device.
 8. The system of claim 7, wherein one of the first RFID tag and the second RFID tag is an active tag having a memory that is selectively altered in response to the first signal and the second signal from the master device.
 9. The system of claim 7, wherein the second RFID tag comprises a passive device operatively associated with the microcontroller.
 10. The system of claim 7, further comprising a third RFID tag and a fourth RFID tag operatively associated with the microcontroller, wherein the third RFID tag and the fourth RFID tag are responsive to a third signal at a third frequency and a fourth signal at a fourth frequency from the master device, wherein the microcontroller changes operation of the home appliance between a third state and a fourth state in accordance with the response to the third signal by the third RFID tag and the fourth signal by the fourth RFID tag.
 11. The system of claim 10, wherein the first state, the second state, the third state, and the fourth state represent one of low, medium, high and critical modes of operation for the home appliance.
 12. The system of claim 9, wherein the first frequency, the second frequency, the third frequency, and the fourth frequency are different from one another.
 13. The system of claim 9, wherein the first state and second state define operation of the home appliance in different energy saving operational modes. 